Chain grate



Man, 1926. "1,583,085 f D. G. MEIKLEREID CHAIN GRATE Filed May 13, 1919 2 Sheets-Sheet l mmvroa 1 M ATTORNEYS.

. Mi a 192s. +,5s-3;0as-'- D. G. MEIKLEREID CHAIN (IRATE 4 Filed May 13, 1919 2 Sheets-Sheet 2 llllmffnllll i v i 1- v I v 'INVENIOR.

ATTORNEYS. v

Patented May 4, 1926.

UNlED DUNCAN GRAHAM MnrKLEnnrn, or LEE, ENGLAND, Assrenon 'ro THE BABCOCK & WILCOX COMEANY, or enronnn, new A CGBFORATION or JERSEY.

Application filed May 13,

To all whom it may concern:

Be it known that I, DUNCAN GRAHAM Mnninnnnin, a subject of the King of Great Britain, residing at 98 Burnt Ash Hill Lee, county of Kent, England, have invented certain new and useful Improvements in Chain Grates, of which the following is a specification. 1

This invention relates to chain grates and has for its primary object to proiiide improved constructions of grate bar linl s such that with the combination of links assembled and enclosed at top and bottom the escape of air between the links and between the top and bottom'clcsures when the mechanical stoker is working with air under pressure is largely prevented. A further object is to provide a construction of outside grate bar link such that a. sufficient air seal may be maintained between the outside grate bar links and the carriage frame of the mechanical SlZOkGIK The invention also relates to the particular construct-ion of grate links illustrated 1n the accompanying drawings.

My invention will best be understood by reference to the accompanying drawing, in which like reference characters indicate like parts, and in which Figure 1 is a side view with parts in section of'a chain grate stokcr embodying my invention; Fig. 2 is a plan view of a portion thereof; Fig. 3 is a plan view illustrating a central link, an outer link, and an intermediate link, in assembled position; Fig. t is a side elevation of part shown in Fig. 3 as viewed from the right; Fig. 5 isa side elevation of a central link; Fig. 6 is a vertical section through the central link on the line 66 of Fig.- 5; 7 is a vertical section through an outer link; Fig. 8 is a side elevation of an intermediate link; Fig. 9 is an end elevation of the intermediate link; Fig. 10 is a vertical section of the intermediate link on the line 101O of Fig. 8; Figll is a plan view of a slightly -modified form of intermediate link, Fig. 12 shows diagrammatically the arrangement of the illustrated form of top and bottom covering plates, and Fig. 131's a vertical section on line 1313 of Fig. 2.

Referring now to the drawings, the grate is ncde up of a number of connecting pins andlinksof three different forms, most of the links being the cei itral links it: its

1919. Serial NO. 295,822.

shown best in Figure 2, these central links have reduced end portions which perm-it them to be closely spaced along each of the pins 10, and a widened surface portion at he middle to fill up the larger part of the space between the, pins. I Each of the central linksll is provided with the widened surface portion 12 and a narrower surface portion 13, this latter being substantially the same width as the eyes or bearings- 14 through which the pins 10' pass. Beneath the surface portions 12 and 13 is a vertical supporting web 15 which may be extended at each end beyond the eyes 14, as shown. at 16 and 17, the surface portion extendingfbeyond the web as shown. Preferably, each side of the surfacefportions' 12 and 13 is ribbed, as shown in Figures 8 and 5.

Beneath the. wide surface portion 12 and extending to the bottom of the web 15 is a vertical rib 18 on each side of the link extending flush with the surface portion, for a purpose to be more fully hereinafter referred to.

The arrangement of the central links assembled in the chain, is best shown in Figure 2, in which it will be seen that the widened portions 12 of adjacent links come relatively close together and that the narrowed portions 13 arespaced apart a suf iicient distance to allow the corresponding narrow portion 13 of a link on the other side ofthe connecting pin to be placed therebetween. This arrangement provides fora substantial filling up of the surface of the chain except for the narrow openings between the links, which openings arefurther augmented by the diagonal air channels eX- tending across the sides of the surface portions 12 and 13 as illustrated in Figs. 5 and 6. It will be also noted that the vertical ribs 18 on'adjacentlinks come edge to edge so as to form a relatively closed rib extending transversely of the grate. It will also be observed that at the connecting pins the eyes 14, by reason of their close as sembly on the pins correspondingly, provide arelatively continuous member longitudinally of the pins. 1

In order to seal the chain between the Stoker frameandthe grate I provide marginal links} 26 which general are of a shape similar to that of the central links 11';

that is, each marginal new has reduced pow-" tions through which the connecting pins pass and a widened surface portion to fill up the space which would otherwise be present, these end reduced surface portions being indicated respectively at 21 and 22 and the widened portions at 23. The surface portions of the link are supported by a vertical supporting web 24; and suitable bosses 25 thereon through which bearings are provided for the connecting pins. On the outer side of the link is a flange 26 extending laterally along the lower edge of the web 24 and partly around the extremity of the link, as shown in Figure 4. Said laterally extending flanges are preferably relatively thin and extend beneath the link centers as shown, the space between the ends of said flanges on adjacent links being relatively small and the ends of said flanges being curved to maintain such space substantially constant during the entire travel of the chain. As shown best in Figure 2, this flange is arranged to come closely to the frame of the stoker A.

In order to fill up the space which would otherwise occur between the marginal links, I provide an intermediate link 28 which has reduced surface end portions 29 and a with ened middle portion 30. This link is also provided with eyes or bosses 31 through which the connecting pins extend and a supporting web 32 beneath the surface. On one side only of the intermediate link I provide a vertical rib 33 which cooperates, as shown in Figure 2, with the corresponding rib on the central link 11. The intermediate link 28 illustrated in Figure 11 differs from that shown in Figures 8, 9 and 10 only in having diagonally extending air channels on both sides rather than one side only, as shown in the latter figures.

Referring now to Figure 1 which shows an illustrative form of chain grate stoker provided with my novel connecting links, A represents the side frame of the stoker with which the flanges 26 of the outside links cooperate, B is the hopper, and C indicates air seals for the stoker, disposed between the upper and lower runs of the chain grate, air under pressure being supplied through the openings It will be noted that in order to save weight, I have cut away the lower portion of each link. If thiswere done without a special arrangement of links, and the stoker were operated with a forced blast, there would be an undue amount of air leakage between the chain grate and any closure that might be placed beneath the links of the grate. This air leakage would naturally occur between the runs of the chain and the air would pass alon the chain in the direction of the chain travel. By providing the air seal in connection with the links which I have devised, as shown in Fig. 1,

diate links engaging the corresponding" bosses 25 on the outer links and the bosses 14 on the central links. These bosses form a substantially continuous partition or rib extendin from the web 32 of the intermediate link to the margin'of the chain. The space between each unbroken rib is the same as the distance between the pins which engage the links. It will" be seen by referring to the semi-diagramn atie Fig. 12 that if the plate E is long enough to span the space between two of the ribs, there will always be one of the ribs above the plate, and that an air seal is thereby provided. The arrangement therefore results in a chain of relatively light weight in which the lower portion of the chain can be sealed against air leakage.

I also provide a seal F at the top of the grate and beneath the hopper B. The object of this seal is to prevent the air blast from passing upward between the links directly at the rear of the hopper B and through the fuel in the hopper. The air which passes up through the fuel in the hopper leads to a wasteful process and in some instances may cause trouble through igniting the coal in the hopper.

It will be seen, therefore, that by my novel arrangement I have provided first a relatively light chain in which substantially all of the surface is filled up and second, an arrangement by which, although the links themselves are reduced in weight, there will be little or no air lost by leakage over the air seal through the chain itself and that substantially all of the air will be obliged to find its passage vertically through the chain and into the bed of coal.

V hat I claim and desire to secure by Let ters Patent of the United States is 1. A chain grate comprising links pivotal.- ly connected together and eaih formed with a relatively wide surface portion and a rela tively narrow supporting web. said webs being provided at parts intermediate vertical planes through the pivotal points of said links with laterally extending ribs limited in extent by the edges of said surface portions and forming a practically continuous transverse rib on the inside of the chain and across the maj or portion thereof.

2. A chain grate comprising-links pivotal 1y connected together and each formed with a relatively wide surface portion and a relatively narrow supporting web, said webs being provided at parts intermediate vertical planes through the pivotal pointsof said links with laterally extending ribs limited in extent by the edges of said surface portions and forming a practically continuous transverse rib on the inside of the chain and across the major portion thereof, and an air seal or closure disposed adjacent to the inner 7 surface of the chain and of sutficient length to span the space between two successive transverse ribs of the chain.

3. A chain grate composed of connecting pins and links pivotally connected together by said pins and closely arranged thereon, each link having a relatively wide surface portion and a relatively narrow supporting web, and an air seal located between the upper and lower runs of the chain and adjacent thereto, certain of said links being provided at parts intermediate vertical planes through the pivotal points of said links with laterally extending ribs limited in extent by the edges of said surface portions and forming a practically continuous rib on the inside of the chain and across the major portion thereof, cooperating with said seal to limit the flow of air through the links of said grate and longitudinally thereof.

i. A chain grate comprising connecting pins and links pivotally connected together by said pins and closely arranged thereon, a frame for the stoker adjacent to said chain, each link having a relatively wide surface portion and a relatively narrow supporting web, said supporting webs being provided at parts intermediate vertical planes through the pivotal points of said links with laterally extending ribs limited in extent by the edges of said surface portions, the ribs of the various links located side by side forming a practically continuous transverse web on the inside of the chain and across the major portion thereof, and an air seal located between the two runs of the chain and adjacent thereto, the outer links being provided with lateral flanges extending close to the frame of the stoker.

5. A chain grate stoker comprising side frames, central links each formed with vertical ribs one on each side, marginal links each formed on one side with a curved flange extending along the lower edge and a part of each extremity of the link, complemental or intermediate links each formed with a vertical rib on one side only, and pins connecting said links to form a chain grate with a substantially continuous barrier to the flow of air through said links parallel to the run of the chain, said curved flanges forming a barrier to the flow of air between the chain and the side frames of the stoker.

6. Alink for a chain grate stoker having openings at its ends for receiving connecting pins and comprising a web, a surface portion extending laterally beyond said web and wider at its middle portion than at its ends, and a vertical rib on said web at a part intermediate said openings, the outer side of which rib is substantially parallel with said web and extends flush with said widened surface" portion and substantially to the lower side of said link.

7 A chain grate comprising links each formed with arelatively wide surface portion and a relatively narrow supporting web, said webs being provided with laterally extending ribs forming a practically continuous transverse rib on the inside of the chain, a hopper for the chain grate, a closure plate disposed at the bottom of the hopper and adjacent the chain for preventing air from passing through the chain grate and into the hopper, and an air seal or closure disposed adjacent to the inner surface of the chain grate beneath said closure plate and of sufficient length to span the space between two successive transverse ribs of the chain.

8. A link for a chain grate stoker having a relatively wide surface portion and a relatively narrow supporting web, the surface portion being relatively wide at its intermediate portion and relatively narrow at its ends, the narrow ends being provided with openings for the reception of supporting rods, said web being provided intermediate said openings with a rib extending laterally with its outer edge flush with the edge of the surface portion of the link.

9. In an endless chain grate stoker, a frame marginal links having laterally extending, relatively thin flanges with the outer edges thereof adjacent said frame and said flanges extending beneath the link pivot centers, the spaces between the ends of said flanges on adjacent links being relatively small and the ends of said flanges being curved to maintain such spaces substantially constant during the entire travel of the chain.

10. A chain grate comprising central, interinediateeand marginal links, each provided with a comparatively wide surface portion and con'iparatively thin vertical longitudinal webs, each intermediate link being provided with a rib on one side only of its web extending laterally substantially flush with the surface portion, each central link being provided on each side of its web with a rib extending laterally substantially flush with its surface portion, the ribs of side by side central and intermediate. links forming a substantially continuous transverse rib extending transversely of the chain from the web of an intermediate link on one side to the web of an intermediate link on the other side, said marginal links being provided with. laterally. extending flanges forming'a barrier to the flow of air between the chain and the side frames of the stoker.

11. A chain grate comprising central, in termediate and marginal links, each provided with an extended surface portion and vertical longitudinal webs, each interme diate link being provided with a rib on one side only of its web extending laterally substantially flush with the surface portion, each central link being provided on each side of its web with a rib extending laterally substantially flush with its surface portion, the ribs of side by side central and intermediate linrs forming a substantially continuous transverse rib extending transversely of the chain from the web of an intermediate link on one side to the web of an intermediate link on the other side, and means forming transverse partitions between the webs of said intermediate links and the margins of the chain, said marginal links being provided with laterally extending flanges forming a barrier to the flow of air between the chain and the side frames of the stoker.

12. A chain grate comprising central, in-

termediate and marginal links, each provided with an extended surface portion and a vertical longitudinal web, each intermediate link being provided with a rib on one side only of its web extending laterally sub stantially flush with the surface portion, each central link being provided on each side of its web with a rib extending laterally substantially flush with its surface portion, the ribs of side by side central and intermediate links forming asubstantially continnous transverse rib extending transversely of the chain from the web of an intermediate link on one side to the wee of an intermediate link on the other side said marginal. links being provided with. laterally extend ing flanges forming a barrier to the flow of air between the chain and the side frames of the Stoker and a seal located between the runs of the chain and comprising engaging members spanning the distance between successive ribs or partitions.

In testimony whereof I have hereunto signed my name.

DUNCAN GRiiHAlJ MEIKLEREID. 

